Arrangement of electrodes on a display panel utilizing gas discharge

ABSTRACT

A self-shift plasma display panel based on the surface discharge is disclosed. This plasma display panel has two electrode groups of shift electrodes and channel electrodes which are positioned so that the two types of electrodes cross at right angles on the same substrate facing a discharge space filled with gas capable of ionization. The shift electrodes are alternately connected to first and second buss at intervals of one electrode, and the channel electrodes are alternately connected to third and fourth buss at intervals of one electrode. The above-mentioned four buss are connected to a four phase alternating voltage source. A discharge spot produced between a shift electrode and a channel electrode is shifted along the channel electrode by means of the four phase alternating voltage applied to the four buss in order.

United States Patent Andoh et a1. 1 1 Aug. 5, 1975 [54] ARRANGEMENT OF ELECTRODES ON A 3.701.924 10/1972 Glaser 315/169 TV X DISPLAY PANEL UTILIZING GAS 3,781,599 12/1973 Bonn 315/169 R X DISCHARGE Prjmary E.\'umir1erJames B. Mullins [75] Inventors: Shlzuo Andoh; Nonhlko Nakayama Attorney, Agent, or Firm-Allan Ratner; Nelson E.

both of Kobe, Japan Kimmelman [73] Assignee: Fujitsu Limited, Japan [22] Filed: Mar. 6, 1973 ABSTRACT [21] Appl 338,553 A self-shift plasma display panel based on the surface discharge is disclosed. This plasma display panel has two electrode groups of shift electrodes and channel Foreign Application Priority Data electrodes which are positioned so that the two types Mar. 15, 1972 Japan 47-25801) of electrodes cross at right angles on the same substrate facing a discharge space filled with gas capable [52] U.S. C1. 315/169 R; 313/188 of ionization. The shift electrodes are alternately con- [51] Int. Cl. H05B 37/00 nected to first and second buss at intervals of one [58] Field of Search 315/169 R, 169 TV; electrode, and the channel electrodes are alternately 340/324 M; 313/188 connected to third and fourth buss at intervals of one electrode. The above-mentioned four buss are con- [56] References Cited nected to a four phase alternating voltage source. A UNITED STATES PATENTS discharge spot produced between a shift electrode and 3.499.167 3/1970 Baker et .11. 315/169 Channel electrode is Shifted chmnel clcc' 3646384 2/1972 315/169 R X trode by means of the four phase alternating voltage 3671938 6/1972 315/169 R X applied to the four buss in order.

3.681.655 81972 315/169 R 3.684.918 8/1972 Schmorsac 315/169 TV X 10 21 Drawmg F'gures PATENTED AUG 5 975 SHEET PATENTEU M15 5 I975 SHEEI Fig. 3 PRIOR ART 3 AC. SOURCE l2 BAWCD KK PATENTEU 51975 3898515 sum 3 PATENTEU RUB 5l975 SHEET Fig- 9 '2 BA CDKK ARRANGEMENT OF ELECTRODES ON A DISPLAY PANEL UTILIZING GAS DISCHARGE The present invention relates to the construction of electrodes of a panel utilizing gas discharge, more specifically to the novel construction of electrodes for providing a shift channel of a discharge spot in a self-shift or self-scan plasma display panel based on the surface discharge.

Generally, in a self-shift type panel utilizing a gas discharge having a function of shifting a discharge spot. a plurality of parallel shift electrodes connected to a polyphase electric source are faced via a dielectric layer to a discharge gap filled with ionizable gas. When a discharge spot is produced by applying a voltage to the first shift electrode, the discharge spot can be shifted in turn in the direction which is at right angles to the shift electrodes by applying a sustaining voltage at polyphase to the shift electrodes successively. However, it is necessary to electrically or mechanically limit the direction of the shift action for the purpose of carrying out said shift action in the direction which is at right angles to the shift electrodes. If this is not done the direction of the shift action of the discharge spot deviates from the right angle with regard to the shift electrodes. For the purpose of determining the shift direction of the discharge spot, it has been proposed that electrical insulation barriers or mechanical insulation barriers be provided in a direction parallel to the shift action. However, such insulation barriers not only make the structure complicated, but also the assembly of the structure is very troublesome. Further, the space between columns becomes inevitably large and the displayed figure becomes unsightly.

An object of the present invention is to provide a construction of electrodes of a panel utilizing a gas discharge which overcomes the above-mentioned drawbacks.

Another object of the present invention is to provide a panel utilizing a gas discharge having a second group of electrodes which constitutes a shift channel arranged at right angles to the shift electrodes, and carries out the self-shift or self-scan due to the surface discharge. This second group of electrodes, arranged longitudinally and at right angles to the shift electrodes, are hereinafter called channel electrodes, and this channel is defined as the structure in which the discharge can be shifted separately only along a predetermined passage.

Further features and advantages of the present invention will be apparent from the ensuing description, with reference to the accompanying drawings, to which, however, the scope of the invention is in no way limited.

FIG. 1 is a general view of the typical plasma display panel;

FIG. 2 is a sectional view of the plasma display panel shown in FIG. 1;

FIG. 3 is a plan view of the conventional plasma display panel having a function of self shifting the discharge spot;

FIG. 4 is a plan view of one embodiment of the construction of electrodes of plasma display panel having a function of self shifting the discharge spot according to the present invention;

FIG. 5A is a plan view of another embodiment of the construction of electrodes plasma display panel having a function of self shifting the discharge spot according to the present invention;

FIGS. 58 and 5C are two examples of sectional views along a-a, 12-12 of the plasma display panel shown in FIG. 5A;

FIG. 6A is a plan view of further embodiment of the construction of electrodes of the plasma display panel having a function of self shifting the discharge spot according to the present invention;

FIGS. 63 and 6C are two examples of sectional views along c-c, d-d of the plasma display panel shown in FIG. 6A;

FIG. 7A is a plan view of still further embodiment of the construction of electrodes of the plasma display panel having a function of self shifting the discharge spot according to the present invention;

FIGS. 78 and 7C are two examples of sectional views along e-e, f-f of the plasma display panel shown in FIG. 7A;

FIGS. 8A 86 are time charts explaining the method of driving the electrodes of the display panel utilizing gas discharge according to the present invention;

FIG. 9 is still another embodiment of the construction of electrodes of the plasma display panel according to the present invention.

Referring to FIG. I, a display device utilizing a gaseous discharge 1 has a pair of supporting substrates 2 and 2a. The supporting substrate 2 provides a group of electrodes 3 arranged in columns, which is parallel to a vertical axis; dielectric layer 4 covers the group of electrodes 3. The supporting substrate 2a provides a group of electrodes 3a arranged in rows. which is parallel to a horizontal axis; dielectric layer 4a covers the group of electrodes 3a. The supporting substrates 2 and 2a are positioned in spaced parallel relation to the groups of electrodes 3 and 3a respectively. As shown in FIG. 2 these parallel rows and columns are separated from each other by a gap 5. This gap 5 is filled with a rare gas having suitable pressure and capable of ionization. When the device I is utilized for display purposes, it is necessary that, at least, one of the substrates 2, 2a and one of the dielectric layers 4, 4a are transparent.

In the above-mentioned display device utilizing gas discharge 1 shown in FIGS. 1 and 2, when an electric voltage higher than the firing voltage V; is selectively applied between the groups of electrodes in columns 3 and rows 3a, each cross point of the electrodes in columns and rows discharges into the gap 5 filled with an ionizable gas. At the time of this discharge, a wall charge is formed on the surfaces of the dielectric layers 4 and 40 corresponding the above-mentioned cross point. With the effect of this wall charge the discharge, which once generated is sustained with the pulsive sustaining voltage V, smaller than the firing voltage V,, is continued. That is, the information which inputs as the voltage exceeding the firing voltage V; is kept in memory by the above-mentioned wall charge.

Next, the plasma display device utilizing gas discharge having a function of self shifting the discharge spots of surface discharge type according to the prior art will be given with respect to FIG. 3. Referring to FIG. 3, this device provides a plurality of shift electrodes 12, 13, 14, 15, which are arranged in parallel and connected at intervals of two electrodes to common buss of a three phase alternate current electric source. Also provided is a plurality of write electrodes which are arranged in every column longitudinally along the first shift electrode 12. These electrodes 11, l2, l3, l4, l5, etc., are covered with a dielectric layer and face a gap filled with gas capable of ionization.

When the firing voltage is supplied between selected write electrode 11 and the first shift electrode 12, a discharge spot 17 is produced between these two electrodes. In this case, when the three phase sustaining voltage is commutated to shift electrodes in order, the above-mentioned discharge spot is shifted in a direetion at right angles to the shift electrodes in order by the primary current effect. The primary current effect is a phenomenon by which the firing voltage of an adjacent dischargeable point is decreased due to the supplying of electrons, ions and metastable atoms produced by discharge. However, to carry out the abovementioned shift action in each column respectively, it is required that each column be mechanically or electrically separated in the direction of the shifting of the discharge spot. To achieve this purpose, it has been proposed that mechanical insulation barriers 16 be provided between each column for the purpose of preventing the deviation of the discharge spot as shown in the direction 19. However, these mechanical barriers 16 not only make the structure complicated, but also the assembly work is very troublesome. Further, the space between columns becomes inevitably large and the displayed figure becomes unsightly. It has also been pro posed that other electrodes be provided in the center of each column or between each column; the voltage supplied to these other electrodes thereby separating electrically the mutual effect between the columns. However, reliable functioning can not be anticipated with this method.

The preferable embodiment according to the present invention will now be explained with respect to FIGS. 4 9. FIGS. 4 and A are examples of the present invention. Referring to FIGS. 4 and 5A, a write electrode 21 and parallel shift electrodes 22, 23, 24, 25, are arranged parallel to each other. A plurality of pairs of the channel electrodes 30 and 31 are arranged at right angles to the shift electrodes so as to constitute the shift channels along them. The shift electrodes 22, 23, 24, 25, are alternately connected to common buss terminals A and B, and the channel electrodes 30 and 31 are also alternately connected to common buss terminals C and D. These terminals A, B, C and D are connected successively to a four phase alternating electric signal source. It is very effective if the electrode channels 30 and 31 are further provided with alternate branches 26 and 27, as shown in FIGS. 5A, 5B and 5C, so as to facilitate the discharge between the shift electrodes and the channel electrodes. However these branches 26 and 27 are not absolutely necessary. Electrodes 28 and 29 are keep alive electrodes, or primary electrodes that easily produce the discharge. It is understood that the horizontal shift electrodes 22, 23, 24, and the vertical channel electrodes 30, 31 are insulated from each other on the same substrate by a well known cross over technique. FIG. 5B shows a section along line a-a of FIG. 5A, and FIG. 5C shows a section along line bb of FIG. 5A. FIGS. 58 and 5C clarify the mutual relationship between the shift electrode 22, the channel electrodes 30 and 31, the discharge space 32, the dielectric layer 33, the glass substrate 34 and the glass cover 35.

In the discharge panel shown in FIG. 4 and FIGS. 5A 5C, the discharge is first produced between the write electrode 21 and the channel electrode 30 by applying a firing voltage between them. When the write electrode 21 is provided independently every column, and firing voltages are selectively applied to the write electrodes, the discharge spot is also produced every column. Next the shift action of the discharge spot is carried out by applying a firing voltage between the channel electrode 30 and the shift electrode 22, and a further shift action is carried out by applying a firing voltage between the shift electrode 22 and the channel electrode 31. As a result of this, the discharge spot can be shifted by applying a firing voltage successively in order between electrodes 21 and 30, 22 and 31, 23 and 30, 24 and 31, 25 and 30, In the embodiment shown in FIG. 4 and FIGS. 5A 5C, the construction of the shift channel requires at least two horizontal shift electrodes and two vertical channel electrodes. Namely, the shift action of the discharge spot in the embodiments of this invention may be performed by an electric signal source of more than four phase.

FIG. 6A shows another embodiment of the construction of the electrodes according to the present invention. FIG. 6B shows a section along line c-c of FIG. 6A and FIG. 6C shows a section along line dd of FIG. 6A. As shown in these figures, the write electrode and every shift electrode and the channel electrode provide projections 38 and 39 in the position where the discharge should be produced and shifted. As a result of this, electric fields are concentrated on part of these projections and the discharge is easily produced and shifted. Consequently the characteristics of the discharge, the separation of the discharge and the margin of the memory of the discharge can be considerably improved. The other principles and functions of the embodiment shown in FIGS. 6A 6C are the same as the embodiment shown in FIGS. 5A 5C, as explained above.

FIG. 7A shows a modified embodiment of the case of FIG. 6A. As shown in FIG. 7A, all channel electrodes 41, 42, except those on both ends provide branches 44 alternately positioned on both sides of the adjacent channel electrodes. Therefore, the number of channel electrodes for same number of the discharge spots in one row can be decreased from that of the case shown in FIG. 6A. As a result of this, the pitch of the discharge spots can be decreased. FIG. 7B shows a section along line ee of FIG. 7A and FIG. 7C shows a section along line ff of FIG. 7A, and these figures clearly show the difference from FIGS. 6A 6C. The other principles and functions of the embodiment shown in FIGS. 7A 7C are same as those shown in FIGS. 6A 6C, as explained above.

When the plasma display panel, used for display in the state of repose, is coupled with the abovementioned discharge panel, used as a scanning portion of the discharge spot, a special self scan memory panel having functions of self scan and memory can be obtained. FIGS. 8A 8G show one example of a driving system wherein the above-mentioned embodiment is used for a scan portion of such self scan memory panel. Referring to FIGS. 8A and 88, pulse voltage V is alternately applied to the keep arrive electrodes K, (28 in FIG. 5A) and K, (29 in FIG. 5A), and discharge is always produced between these electrodes. The discharge to be shifted is generated, as shown for example in FIGS. 8C and 8D, with the voltages V and V,,, which are applied between the write electrode terminal W and the one channel electrode 30 connected buss terminal C, and the discharge so generated is stored. This generated dischargeis maintained by a sustaining voltage V half of which is supplied to the write electrode 21 through the'terminal W the other half being supplied to the one channel electrode 30 through the terminal C. Next, thisdischarge is shifted between the one channel electrode 30 and the first shift electrode 22 with the voltage V which is supplied to said first shift electrode 22 through the terminal A, as shown in FIG. 8E. In this case, the voltage applied between these electrodes is, as shown in the diagram of FIGS. 8D and 8E, the sum of the voltage V and one half of sustaining voltage V,/2, that is, it is defined to exceed the firing voltage under the-condition of receiving the primary current effect from the adjacent discharge spot. Accordingly, although the voltage of the sum of the voltage V and V /2 is applied to all one channel electrodes 30 connected buss terminal C and to all shift electrodes connected buss terminal A, the shifted discharge spot is produced at only adjacent discharge positions.'ln this manner the discharge is shifted to the electrode channel D and the electrode B successively as shown in FIGS. 8F and 8G.

When the panel utilizing gas discharge, having the above-mentioned construction of electrodes, is used for a display panel having a function of self-shift, the write electrode should be divided into W W W,,, corresponding to each shift channel as shown in FIG. 9, for selectively inputting the information to each column.

It is understood that the effect of such construction of the channel electrode according to the present in vention can be considerably increased by combining another method for separating the discharge, for example:

a. A dielectric layer having a high secondary electron emissivity coefficient and a dielectric layer having low secondary electron emissivity coefficient are arranged alternately in parallel on the dielectric layer in the direction along which the discharge should be shifted, and the discharge is shifted in the direction of these dielectric layers by the difference of the secondary elec tron emissivity coefficients.

b. Utilizing field curtains, which are composed of electrodes electrostatically shielding the discharge against the direction in which the discharge should be shifted.

In the above explanation concerning FIGS. 4 through 9, the electrodes are covered with dielectric layer, however, the present invention can be effectively applicable to the case where the electrodes are not covered with dielectric layer and are exposed directly to the discharge space filled with ionizable gas. The memory function is lost in this case, and the exposed electrodes are utilizable as a scan portion for an above described self shift memory panel.

What is claimed is:

1. An arrangement of electrodes on a display panel utilizing gas discharge comprising a first group of electrodes being arranged in parallel facing a discharge space filled with ionizable gas, means for alternately connecting the electrodes of the first group to at least two common terminals,

a second group of electrodes being used in pairs and arranged so as to cross said first group of said electrodes, each electrode of said pairs of electrodes alternately providing between electrodes of said first group of electrodes branches which extend to the inside of said pair of electrodes,

means for alternately connecting the electrodes of the second group to at least two common terminals,

said first group of electrodes and said second group of electrodes are insulated on the same substrate,

a dielectric layer covering said first and second groups of electrodes, and

polyphase alternating electric signals being supplied to said terminals of the first and second group of electrodes, thereby shifting a discharge spot between the electrode of the first group and the electrode of the second group successively in the direction of said second group of electrodes.

2. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 1, further comprising a write electrode being arranged in parallel to the first group of electrodes.

3. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 1 wherein each of said branches provide a projection in the posiutilizing gas discharge comprising a first group of electrodes being arranged in parallel I facing a discharge space filled with ionizable gas, means for alternately connecting the electrodes of the first group to at least two common terminals,

a second group of electrodes being arranged so as to cross said first group of said electrodes, said second group of electrodes except for those on each side alternately provide branches which extend to both sides of the electrode belonging to said second group of electrodes and electrodes belonging to each side of said second group of electrodes alternately provide branches which extend to the inside of said side electrodes,

means for alternately connecting the electrodes of the second group to at least two common termi nals,

said first group of electrodes and said second group of electrodes are insulated on the same substrate, a dielectric layer covering said first and second groups of electrodes, and

polyphase alternating electric signal being supplied to said terminals of the first and second group of electrodes, thereby shifting a discharge spot between the electrode of the first group and the electrode of the second group successively in the direction of said second group of electrodes.

5. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 4, further comprising a plurality of write electrodes being arranged to correspond to each shift channel provided by the second group of electrodes.

6. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 4 wherein each of said branches provide a projection in the position where the discharge should be easily produced.

7. An arrangement of electrodes on a display panel utilizing gas discharge which includes a first group of electrodes on the base plate of said display panel being arranged in parallel facing a discharge space filled with ionizable gas and means for alternately connecting the electrodes of said first group to at least two common terminals for shifting a discharge spot toward the crossing of said first group of electrodes, comprising a. a second group of electrodes being arranged in parallel on said base plate so as to cross said first group of electrodes and being electrically insulated from said first group of electrodes.

b. at least two common terminals alternately connected to said second group of electrodes so as to be used in pairs, each electrode of said pairs of electrodes alternately providing between electrodes of said first group of electrodes branches which extend to the inside of said pairs of electrodes, and,

c. means for supplying polyphase alternating electric signals to said common terminals of said first and second groups of electrodes thereby shifting a discharge spot generated between the electrodes of said first group and second group in the direction of said second group of electrodes.

8. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 7, wherein each of said branches provide a projection in the position where the discharge should be easily produced.

9. An arrangement of electrodes on a display panel utilizing gas discharge. which includes a first group of electrodes on the base plate of said display panel being arranged in parallel facing a discharge space filled with ionizable gas and means for alternately connecting the electrodes of said first group to at least two common terminals for shifting a discharge spot toward the crossing of said first group of electrodes, comprising a. a second group of electrodes being arranged in b. at least two common terminals alternately connected to said second group of electrodes so as to be used in pairs, and,

c. means for supplying polyphase alternating electric signals to said common terminals of said first and second groups of electrodes thereby shifting a discharge spot generated between the electrodes of said first group and second group in the direction of said second group of electrodes.

10. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 9, wherein each of said branches provide a projection in the position where the discharge should be easily produced. 

1. An arrangement of electrodes on a display panel utilizing gas discharge comprising a first group of electrodes being arranged in parallel facing a discharge space filled with ionizable gas, means for alternately connecting the electrodes of the first group to at least two common terminals, a second group of electrodes being used in pairs and arranged so as to cross said first group of said electrodes, each electrode of said pairs of electrodes alternately providing between electrodes of said first group of electrodes branches which extend to the inside of said pair of electrodes, means for alternately connecting the electrodes of the second group to at least two common terminals, said first group of electrodes and said second group of electrodes are insulated on the same substrate, a dielectric layer covering said first and second groups of electrodes, and polyphase alternating electric signals being supplied to said terminals of the first and second group of electrodes, thereby shifting a discharge spot between the electrode of the first group and the electrode of the second group successively in the direction of said second group of electrodes.
 2. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 1, further comprising a write electrode being arranged in parallel to the first group of electrodes.
 3. An arrangeMent of electrodes on a display panel utilizing gas discharge according to claim 1 wherein each of said branches provide a projection in the position where the discharge should be easily produced.
 4. An arrangement of electrodes on a display panel utilizing gas discharge comprising a first group of electrodes being arranged in parallel facing a discharge space filled with ionizable gas, means for alternately connecting the electrodes of the first group to at least two common terminals, a second group of electrodes being arranged so as to cross said first group of said electrodes, said second group of electrodes except for those on each side alternately provide branches which extend to both sides of the electrode belonging to said second group of electrodes and electrodes belonging to each side of said second group of electrodes alternately provide branches which extend to the inside of said side electrodes, means for alternately connecting the electrodes of the second group to at least two common terminals, said first group of electrodes and said second group of electrodes are insulated on the same substrate, a dielectric layer covering said first and second groups of electrodes, and polyphase alternating electric signal being supplied to said terminals of the first and second group of electrodes, thereby shifting a discharge spot between the electrode of the first group and the electrode of the second group successively in the direction of said second group of electrodes.
 5. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 4, further comprising a plurality of write electrodes being arranged to correspond to each shift channel provided by the second group of electrodes.
 6. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 4 wherein each of said branches provide a projection in the position where the discharge should be easily produced.
 7. An arrangement of electrodes on a display panel utilizing gas discharge which includes a first group of electrodes on the base plate of said display panel being arranged in parallel facing a discharge space filled with ionizable gas and means for alternately connecting the electrodes of said first group to at least two common terminals for shifting a discharge spot toward the crossing of said first group of electrodes, comprising a. a second group of electrodes being arranged in parallel on said base plate so as to cross said first group of electrodes and being electrically insulated from said first group of electrodes, b. at least two common terminals alternately connected to said second group of electrodes so as to be used in pairs, each electrode of said pairs of electrodes alternately providing between electrodes of said first group of electrodes branches which extend to the inside of said pairs of electrodes, and, c. means for supplying polyphase alternating electric signals to said common terminals of said first and second groups of electrodes thereby shifting a discharge spot generated between the electrodes of said first group and second group in the direction of said second group of electrodes.
 8. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 7, wherein each of said branches provide a projection in the position where the discharge should be easily produced.
 9. An arrangement of electrodes on a display panel utilizing gas discharge, which includes a first group of electrodes on the base plate of said display panel being arranged in parallel facing a discharge space filled with ionizable gas and means for alternately connecting the electrodes of said first group to at least two common terminals for shifting a discharge spot toward the crossing of said first group of electrodes, comprising a. a second group of electrodes being arranged in parallel on said base plate so as to cross said first group of electrodes and being Electrically insulated from said first group of electrodes, said second group of electrodes except for those on each side alternately provide branches which extend to both sides of the electrode belonging to said second group of electrodes and electrodes belonging to each side of said second group of electrodes alternately provide branches which extend to the inside of said side electrodes, b. at least two common terminals alternately connected to said second group of electrodes so as to be used in pairs, and, c. means for supplying polyphase alternating electric signals to said common terminals of said first and second groups of electrodes thereby shifting a discharge spot generated between the electrodes of said first group and second group in the direction of said second group of electrodes.
 10. An arrangement of electrodes on a display panel utilizing gas discharge according to claim 9, wherein each of said branches provide a projection in the position where the discharge should be easily produced. 